Recyclable film with barrier layer

Abstract

A multilayer, monoaxially stretched, recyclable film (1) for a laminate (7). The film (1) has outer layers (3) and at least one inner barrier layer (6), with a tie layer (5) arranged between each of these. At least one further, functional intermediate layer (4) is arranged between each of the outer layers (3) and the barrier layer (6).

1 . A multilayer, monoaxially stretched, recyclable film ( 1 ) for a laminate ( 7 ), the film ( 1 ) comprising:
 outer layers ( 3 ) and at least one inner barrier layer ( 6 ), and a tie layer ( 5 ) being arranged between the outer layers ( 3 ) and the at least one inner barrier layer ( 6 ); and   at least one further functional intermediate layer ( 4 ) being arranged between the outer layers ( 3 ) and the at least one inner barrier layer ( 6 ).   
     
     
         2 . The film according to  claim 1 , wherein the outer layers ( 3 ) have a density which is a factor higher than the at least one functional intermediate layer, the value of the factor being more than 1.002and less than 1.20. 
     
     
         3 . The film according to  claim 1 , wherein a density of the outer layers ( 3 ) has a value of more than 0.941 g/cm 3 . 
     
     
         4 . The film according to  claim 1 , wherein a density of the at least one functional intermediate layer ( 4 ) has a value of more than 0.91 g/cm 3  and of less than 0.940 g/cm 3 . 
     
     
         5 . The film according to  claim 1 , wherein the at least one functional intermediate layer ( 4 ) comprise a bimodal polyethylene, wherein the bimodal polyethylene is a terpolymer, and further wherein the terpolymer is a bimodal ethylene/1-butene/C6-C12-alpha-olefin terpolymer. 
     
     
         6 . The film according to  claim 1 , wherein a density of the the layer ( 5 ) has a value of less than 0.915 g/cm 3 . 
     
     
         7 . The film according to  claim 1 , wherein the barrier layer ( 6 ) is formed as an ethylene-vinyl alcohol copolymer layer. 
     
     
         8 . The film according to  claim 1 , wherein the tie layer ( 5 ) comprises a maleic anhydride modified polyethylene and a polyethylene, wherein a density of the tie layer ( 5 ) is more than 0.880g/cm 3 , preferably more than 0.900 g/cm 3  and is less than 0.940 g/cm 3  and has a melt flow rate (at 190° C. at 2.16 kg) according to ASTM D 1238 that is more than 0.1 g/10 min and is less than 5.0 g/10 min. 
     
     
         9 . The film according to  claim 1 , wherein a melt flow rate (at 190° C. at 2.16 kg) according to ASTM D 1238 of the tie layer ( 5 ) is similar to a melt flow rate of the functional intermediate layer ( 4 ), wherein the melt flow rates of the tie layer ( 5 ) and the functional intermediate layer ( 4 ) differ by a factor of less than 1.5. 
     
     
         10 . The film according to  claim 1 , wherein the film ( 1 ) has a gloss according to DIN EN ISO 2813 of less than 7%. 
     
     
         11 . The film according to  claim 1 , wherein the film ( 1 ) has an oxygen transmission rate of less than 10 cm 3 /m 3 -day-bar, measured at 23° C. and 0% rH. 
     
     
         12 . The film according to  claim 1 , wherein the film ( 1 ) has a water vapour transmission rate of less than 50 g/m 2  in 24 h according to ASTM D6701-01. 
     
     
         13 . The film according to  claim 1 , wherein the film ( 1 ) is stretched monoaxially in a machine direction by more than a factor of 2.0 and is stretched in the machine direction by less than a factor of 7.0. 
     
     
         14 . The film according to  claim 1 , wherein an imprint ( 2 ) is arranged directly on an outermost one of the outer layers ( 3 ) of the film ( 1 ). 
     
     
         15 . The film according to  claim 1 , wherein the film ( 1 ) has a thickness of less than 60 μm, and more than 5 μm. 
     
     
         16 . The film according to  claim 1 , wherein a density of the film ( 1 ) is less than 0.99 g/cm 3 , and iis more than 0.60 g/cm 3 . 
     
     
         17 . The film according to  claim 1 , wherein the multilayer structure of the film ( 1 ) is symmetrical. 
     
     
         18 . The film according to  claim 1 , wherein the film ( 1 ) has at least one additional, outer layer ( 9 ) which is formed from an ethylene-vinyl alcohol copolymer layer (EVOH) or from polyamide (PA). 
     
     
         19 . The film according to  claim 1 , further comprising at least one further outer layer for producing a mattness which has no fillers, the film ( 1 ) thereby having a haze value according to ASTM D1003 of more than 65%. 
     
     
         20 . The film according to  claim 1 , wherein at least one outer layer ( 3 ) has a proportion of polypropylene, the proportion being more than 5% by weight and less than 50% by weight.